Section 183.542 - Fuel systems(a) Each fuel system in a boat must have been tested by the boat manufacturer and not leak when subjected to the greater of the following pressures: (1) Three pounds per square inch; or(2) One and one-half times the pressure created in the lowest part of the fuel system when it is filled to the level of overflow with fuel.(b) The test pressure shall be obtained with air or inert gas.CGD 81-092, 48 FR 55737, Dec. 15, 1983